Don't raise contact events for qdel ents (#4126)

Robust.Shared/GameObjects/EntityManager.cs

@@ -77,6 +77,11 @@ namespace Robust.Shared.GameObjects
         public event Action<EntityUid>? EntityInitialized;
         public event Action<EntityUid>? EntityStarted;
         public event Action<EntityUid>? EntityDeleted;
+
+        /// <summary>
+        /// Raised when an entity is queued for deletion. Not raised if an entity is deleted.
+        /// </summary>
+        public event Action<EntityUid>? EntityQueueDeleted;
         public event Action<EntityUid>? EntityDirtied; // only raised after initialization
 
         private string _xformName = string.Empty;
@@ -637,8 +642,11 @@ namespace Robust.Shared.GameObjects
 
         public virtual void QueueDeleteEntity(EntityUid uid)
         {
-            if(QueuedDeletionsSet.Add(uid))
-                QueuedDeletions.Enqueue(uid);
+            if (!QueuedDeletionsSet.Add(uid))
+                return;
+
+            QueuedDeletions.Enqueue(uid);
+            EntityQueueDeleted?.Invoke(uid);
         }
 
         public bool IsQueuedForDeletion(EntityUid uid) => QueuedDeletionsSet.Contains(uid);

Robust.Shared/Physics/Systems/SharedPhysicsSystem.Contacts.cs

@@ -164,6 +164,21 @@ public abstract partial class SharedPhysicsSystem
             4096);
 
         InitializePool();
+        EntityManager.EntityQueueDeleted += OnContactEntityQueueDel;
+    }
+
+    private void ShutdownContacts()
+    {
+        EntityManager.EntityQueueDeleted -= OnContactEntityQueueDel;
+    }
+
+    private void OnContactEntityQueueDel(EntityUid obj)
+    {
+        // If an entity is queuedeleted then we want to purge its contacts before SimulateWorld runs in the same tick.
+        if (!TryComp<PhysicsComponent>(obj, out var physicsComp))
+            return;
+
+        DestroyContacts(physicsComp);
     }
 
     private void InitializePool()

Robust.Shared/Physics/Systems/SharedPhysicsSystem.cs

@@ -250,6 +250,7 @@ namespace Robust.Shared.Physics.Systems
         {
             base.Shutdown();
 
+            ShutdownContacts();
             ShutdownIsland();
             _configManager.UnsubValueChanged(CVars.AutoClearForces, OnAutoClearChange);
         }